1. Technical Field
This disclosure relates generally to a brake system for vehicles which works to control braking force applied to, for example, an automobile.
2. Background Art
Japanese Patent First Publication No. 2012-192776 has proposed a collision avoidance system which works to automatically brake a vehicle to avoid an accident with an obstacle present ahead of the vehicle when it is determined that there is a probability of collision with it.
Japanese Patent First Publication No. 2011-240872 teaches a brake system for automobiles which is equipped with a brake simulator and a hydraulic booster. The brake simulator works to imitate an operation of a typical brake system, that is, make the driver of the vehicle experience the sense of depression of a brake pedal. The hydraulic booster serves to create a master pressure using the pressure of brake fluid in an accumulator in response to depression of the brake pedal. The master pressure is delivered to friction braking devices installed in the vehicle.
The collision avoidance system, as taught in the former publication, is expected to be used with a typical automotive brake system. The former publication is silent about how to employ the collision avoidance system with the hydraulic booster. A combination of the collision avoidance system and the hydraulic booster, therefore, would result in increased number of solenoid valves, hydraulic pipes, or control mechanism making up the brake system to achieve the collision avoidance, thus leading to lowered mountability of the brake system in automotive vehicles.